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Figure 9.2. Codon frequencies in human genes and locations of nondegenerate, two- and fourfold degenerate sites.

Figure 9.2Codon frequencies in human genes and locations of nondegenerate, two- and fourfold degenerate sites

Observed codon frequencies were derived from an analysis of 1490 human genes by Wada et al. 1990. Note that although eight of the 61 first base positions are twofold degenerate, about 96% of all possible substitutions at the first base position are nonsynonymous. 100% of base substitutions at the second base position are nonsynonymous, but only about 33% of those at the third base position.

From: Chapter 9, Instability of the human genome: mutation and DNA repair

Cover of Human Molecular Genetics
Human Molecular Genetics. 2nd edition.
Strachan T, Read AP.
New York: Wiley-Liss; 1999.
Copyright © 1999, Garland Science.

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